/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.streaming.api.runners.python.beam;

import org.apache.flink.annotation.Internal;
import org.apache.flink.python.env.PythonEnvironmentManager;

import org.apache.beam.model.pipeline.v1.RunnerApi.Environment;
import org.apache.beam.runners.fnexecution.control.JobBundleFactory;
import org.apache.beam.runners.fnexecution.control.StageBundleFactory;

import java.util.ArrayList;
import java.util.List;

/**
 * The set of resources that can be shared by all the Python operators in a slot.
 */
@Internal
public final class PythonSharedResources implements AutoCloseable {

	/**
	 * The bundle factory which has all job-scoped information and can be used to create a {@link StageBundleFactory}.
	 */
	private final JobBundleFactory jobBundleFactory;

	/**
	 * An environment for executing Python UDFs.
	 */
	private final Environment environment;

	/**
	 * Keep track of the PythonEnvironmentManagers of the Python operators in one slot.
	 */
	private final List<PythonEnvironmentManager> environmentManagers;

	/**
	 * Keep track of the number of Python operators sharing this Python resource.
	 */
	private int refCnt;

	PythonSharedResources(JobBundleFactory jobBundleFactory, Environment environment) {
		this.jobBundleFactory = jobBundleFactory;
		this.environment = environment;
		this.environmentManagers = new ArrayList<>();
		this.refCnt = 0;
	}

	JobBundleFactory getJobBundleFactory() {
		return jobBundleFactory;
	}

	Environment getEnvironment() {
		return environment;
	}

	void addPythonEnvironmentManager(PythonEnvironmentManager environmentManager) {
		environmentManagers.add(environmentManager);
		refCnt++;
	}

	/**
	 * Release a Python operator which shares this Python resource. Returns true if there
	 * are no more Python operators sharing this Python resource.
	 */
	boolean release() {
		refCnt--;
		return refCnt == 0;
	}

	@Override
	public void close() throws Exception {
		jobBundleFactory.close();
		for (PythonEnvironmentManager environmentManager : environmentManagers) {
			environmentManager.close();
		}
	}
}
